#Raspberry Pi Camera ASCIIizer
###Description: It is a Raspberry Pi hooked up to a camera and an LCD screen as well as. When a button is pressed the camera will take a picture, and the Raspberry Pi will turn it into an image that can be put on the LCD screen (shrink it, make it two color). Then the Raspberry Pi will display the image on the LCD screen either in two color format or ASCII format (matches each 6x8 block of the image to the closest looking ASCII character). ASCII format can be toggled by a button. The program will be written in Python (it would incur significant difficulties to try and use the camera with Java since there is no library for it).
###Goals: ####Completed:
- Created README.md, .gitignore
- Acquired camera for Raspberry Pi
- Acquired LCD screen (Adafruit ST7565)
- Installed Raspberry Pi has operating system
- Text file containing an array of integers representing a tileset of ASCII characters
- Installed Pillow on Pi for image processing
- Image now gets scaled to fit on LCD screen before any processing
- Program converts image to black and white bitmap
- Short Term Plans:
- Write a program that reads an image from a file and makes it a two color image or “ASCIIizes” it.
- Resources:
- http://scipy-lectures.github.io/advanced/image_processing/
- http://docs.scipy.org/doc/numpy/reference/arrays.ndarray.html#array-methods
- http://docs.scipy.org/doc/numpy/reference/generated/numpy.median.html
- http://docs.scipy.org/doc/scipy-0.14.0/reference/generated/scipy.ndimage.imread.html
- http://pillow.readthedocs.org/handbook/tutorial.html
- http://stackoverflow.com/questions/384759/pil-and-numpy
- http://docs.scipy.org/doc/numpy/reference/generated/numpy.delete.html
- http://infohost.nmt.edu/tcc/help/pubs/pil/pil.pdf
- http://stackoverflow.com/questions/17917749/split-a-3-dimensional-numpy-array-into-3x3-grids
- http://effbot.org/imagingbook/image.htm#tag-Image.Image.resize
- Resources:
- Attach camera to Pi
- Capture when a button is pressed and process those images using the above program
- Made program complete in a reasonable amount of time.
####Long Term Plans:
- Write library to allow Pi to control LCD screen (ST7565)
- Attach LCD screen to Pi
###Project Summary:
####Fixing the ASCIIizing
There were a number of bugs in the program that resulted in the ASCIIizing process giving bad output. First I was creating a NumPy array out of the PIL image using np.array(image). I was expecting this to create a 2-dimensional NumPy array where each cell of the array contained a boolean stating whether or not the corresponding pixel in the image was white or black (the image is converted to black and white when loaded). However, np.array(image) was giving me a NumPy array full of garbage values. Further research led me to change that bit of code to np.array(image.getData()).reshape(w,h). After that was fixed I also had to change my code where I was using Image.fromarray(numpyArray) because Image.fromarray(numpyArray) only is able to convert NumPy arrays created using np.array(image). So I instead used SciPy's misc.imsave(numpyArray) to save the image. The final problem with ASCIIizing occurred at the end of the ASCIIization process. During the process I store the image as a one-dimensional array of 6x8 rectangles. At the end of the ASCIIization process I put them back together to form the image. I was using npImage.reshape((w, h)) to put it get it back in the right shape but that did not put the pixels in the right order. The ASCIIizing finally worked correctly when I replaced that operation with one that was more similar to the process that I used to break the image up into pieces.